Process for treating coal or other mineral and apparatus therefor



Oct. 21 1924. 1,512,701

A. A. LOCKWO OD PROCESS FOR TREATING COAL OR OTHER MINERAL AND APPARATUS THEREFOR Filed Nov. 8, 1923 s Sheets-Sheet 1 Oct. 21 1924.

A. A. LOCKWOOD PROCESS FOR TREATING COAL OR OTHER MINERAL AND APPARATUS THEREFOR Filed Nov. 8, 1923 3 Sheets-Sheet 3 Oct. 21 1924.

A. A. LOCKWOOD PROCESS FOR TREATING COAL on OTHER MINERAL AND APPARATUS THEREFOR Filed Nov. 8, 1923 3 Sheets-Sheet 5 Patented Oct. 21, 1924.

UNITED STATES PATENT OFFICE.

PROCESS FOR TREATING COAL OR OTHER MINERAL AND APPARATUS THEREFOR.

Application filed November 8, 1923.

To. all whom it may concern:

Be it known that I, ALFRED ARTHUR LOCKWOOD, a subject of the King of Great Britain, residing at Woodford Lodge, Merton, London, England, have invented a new and useful Improved Process for Treating Coal or Other Mineral and Apparatus Therefor, of which the following is a specification.

This invention has for its object a process which allows the heavy constituentsof coal or other mineral to be very largely and easily separated.

According to this invention coal or other suitable mineral is fed dry on to a shaking table or the like to which a straight to and fro movement is given, which in proximity to its discharge end is considerably narrower (for example, four to eight times more narrow, according to the type of separation process) than the remainder of the table, separation being etfected by a cut out or knife running across the discharge outlet whichpreferably consists of a gap in the bottom of the table.

The cut out may have its top portion so shaped as to form an incline for the cleansed coal.

The process may be a dry separation process or a combination of a dry and a wet process.

In the first case, should the coal be somewhat damp or small, it is desirable and in some cases necessary that a certain quantity of coarse material, such as the larger portions of coal previously cleansed in the (prod. A

ess, should be added to the coal treate very large percentage of shale or yrites present in the coal can be eliminated 1n this.

manner without any admixture of water.

The separation is greatly aided if a blast of air or gases is directed towards the advancing material to be separated in a manner adapted to hold up but not lift the advancing material.

The function of the blast as applied to the treatment of coal in a dry process, is or may be fourfold, for it has been found (1.) That a properly located and adjusted blast will keep back the lighter particles in the dirt and so force them to pass over the cut out.

(2.) That the coal particles becoming gradually piled up by the narrowing of the table are more effectually separated.

(3.) That the process works far more ef- Serial No. 673,552.

ficiently when the coal is, perfectly dry and that this object is aided or achieved by a blast of air or gases especially if the air be heated or hot furnace or other gases are employed for this purpose.

(4.) That the space between the cut out and the table is liable to become choked which is avoided when the blast is directed into such space.

The cleansed product, or uncleansed coal, may subsequently be treated on a similar table while suspended in or floating on water, but in this case it is necessary or desirable that the material should be acted upon by obstacles such as rakes which cause the dirt to be disentangled from the mass A liquid such as oil or the like, usually employed in flotation processes, may be added ,to the water.

The invention is illustrated in the accompanying drawings, in which Figure 1 is a side elevation, partly in section, and Figure 2 a plan with parts removed, of a dry separation apparatus, while Figures 3 and 4 are similar views of a wet separation apparatus.

Referring to Figures 1 and 2, 1 is a shaking table provided with two narrowings 2, situated side by side, and a third narrowing 3 in rear of the first two narrowings. 4 are adjustable cut outs or knives, located at the ends of the narrowings and above holes 5 and 6 in the table. Such holes lead to a passage 7 for dirt or gangue as the case may be; 9 is a pipe conveying air or gases under pressure and 9 9 are flexible pipes terminating in nozzles so situated that the air passes into the passage formed by the cut outs 4 and the table.

10 is a hopper having a delivery 11 into which leads the open end of a branch 9 of pipe 9 whereby the material to be treated is, during its passage on to table 1, given a preliminary drying treatment. 12 is a spout through which the values pass away.

The apparatus works as follows The material in hopper 10 is placed in a spread out condition on the table 1; the mass is driven. forward through the increasingly narrowedareas 2, and piled up; in so doing theparticles of a lesser specific gravity ride over the particles of a greater specific gravity which can pass relatively slowly only through the holes 5 into passage 7 the lighter particles pass over the first cut outs 4 on to the table, where they again become spread out (which operation may be aided by known devices) to become again piled up in narrowingB where the same operation is repeated; the separated lighter particles are led oil? through spout 12. The dirt from the second operation may be led off separately, so constituting middlings.

During these operations a blast of air, for example, has been issuing beneath the cut outs 4 which, as above set out, both aids "the separation and keeps clean the passages for the heavier particles.

Thevalues may then be subjected to a wet separation in the apparatus to be described.

Referrin to Figures 3 and 4, 1 is the shaking ta le, 2 the narrowing, 4 the ad justable cut out, 7 the passage for dirt or gangue, 10 is a hopper, 13 are rakes, 14 is a pipe conveying air under pressure. 15 is a pipe for conveying water on to table 1, 16 is an incline whereby the material is led gently onto the surface of the water and 17 is an atomizer for spraying a liquid, such as mineral oil, on to the surface of the water operated by air assing out under pressure of the open ended pipe 18.

The action of the apparatus is as follows An even stream of water is fed on to table 1 through pipe 15 and the material, say coal, from hopper 10 down incline 16 regularly on to the surface of the water; the coal mainly floats and is propelled by the motion of the table 1 through rakes 13, causing the dirt to become disentangled. In the narrowing 2 a heavier strata is formed over which the cleansed coal climbs. Air as in the table described in Figures 1 and 2, is delivered into the space between the out out 4 and the table.

When an atomized mineral oil or the like is employed, the moisture content of the coal is considerably reduced; in fact, the moisture content need not be greater than that desirable for coke making.

It will be understood that a material may be subjected to more than one dry treatment or combinations of dry and subsequent wet treatments.

'In general I have found that in the dr treatment the material may be crushed to 1 inch mesh, while in the wet treatment; the material may be crushed to less than inch mesh.

What I claim is 1. A process for the dry treatment of coal or other carboniferous material which (0111- prises giving the material. a travelling movement over the surface of a smooth oscillating table, heaping up said material while still travelling separating the heaped material by a cut-out running across a discharge outlet, and delivering a blast of air between the cut-out and the table substantially parallel to the surface of the table upon the material.

2. Apparatus for the separation of coal or other Carboniferous material comprising a table having a straight to and fro move ment, narrowed guide portions on said table, a discharge outlet from the narrowed portion, a cut-out running across the discharge outlet, and means for directing a blast of air between the cut-out and the table against the material and in a direction substantially parallel with the surface of the table.

In testimony that I claim the foregoing as my invention, I have signed my name this 24th day of October 1923.

ALFRED ARTHUR LOGKVVOOD. 

